This invention relates generally to media delivery apparatus, and particularly to air brush construction and media delivery systems.
An air brush is characterized by a compressed air source and a media source integrated into a handheld device. The compressed air originates from an air compressor delivering compressed air by way of an air hose to the air brush. An intricate set of passageways through the structure of the air brush, including a valve for controlling flow of compressed air, deliver the compressed air to the nozzle. Upon actuation of a spray button, a needle valve releases a flow of media near the outlet of the air brush body while concurrent therewith a source of compressed air is released by valve actuation to provide an air flow around and past the needle valve outlet. The air flow draws media from the needle valve outlet and the media is atomized as it exits the body of the air brush within the air flow. In operation, the user depresses the spray button while moving the device in a desired pattern to produce the atomized spray and desired media coverage.
Such handheld air brushes are generally complicated mechanical devices including intricate passageways for delivering media and compressed air and requiring various lever and spring assemblies responsive to actuation of the spray button to produce the desired media flow and air stream at the outlet of the air brush. Such mechanical complexity contributes to a generally expensive item requiring significant maintenance and cleaning.
Because the media flows within the body of the air brush, an air brush requires an intermediate cleaning step between use of different media or media colors. Where media is introduced into the air brush and continuing through to the nozzle outlet, the air brush structure is contaminated with each media or media color used and must be carefully cleaned before a new media or color can be used. In some air brush arrangements, a needle extends along the entire length of the air brush, the needle tip being positioned forward at the nozzle outlet to control media discharge by longitudinal movement of the needle relative to the nozzle outlet. To disassemble such air brush arrangements, the needle is withdrawn from the rear of the air brush, i.e., the tip is pulled through the entire length of the air brush structure. Because the needle tip is necessarily contaminated with media, such procedure contaminates all portions of the air brush having contact with the needle tip during withdrawal of the needle.
Air brushes are typically used in elaborate art work requiring fine control over media delivery and, in many cases, many different media or many media colors in a single project. Cleaning is particularly burdensome in such use of an air brush because the artist often must apply a great number of colors before the work is complete and for each color change an intermediate cleaning step is required.
Air brushes come in a variety of basic configurations. In one arrangement, a cup holds a reservoir of media which flows under the influence of gravity out the bottom of the cup and into the air brush structure. In other air brush arrangements, media is held in a jar positioned below the air brush with a tube extending into the body of media within the jar and communicating with media flow passageways of the air brush. As the air flow draws media from the media passageways, media is pulled from the jar and into the air brush. If an artist wishes to use both types of air brushes, the artist must have available two separate air brushes.
It would, therefore, be desirable for an air brush to be less difficult to use, less complicated in mechanical operation, less expensive, and permit more convenient switching between media or media color.